1. Field of the Invention
The present invention relates to an image displaying method, which makes a correction to fluctuations, and relates to a remote control system for a moving unit, wherein the system uses the method. More particularly, the present invention relates to the remote control system, which functions to remotely control a moving unit such as model cars, model planes, model ships, robots, robotic arms in industrial robots and the like, in motion and in speed of such a moving unit through a control operation of an operation machine, the control operation being conducted by an operator of the operation machine.
2. Description of the Related Art
There have been proposed two devices, one of which is a remote controlled camera device and the other a remotely monitoring system device. Each of these devices is capable of changing its camera's shooting area and the like through a remote control of the device. Japanese Patent application Laid-Open No. Hei 6-38087, for example, has proposed one of the remote controlled camera devices, which one is capable of making a correction to an excessive control amount appearing in controlling its monitoring camera section, wherein a delay in data transmission and a delay in signal processing result in such an excessive control amount. On the other hand, as for the other device, that is, the remotely monitoring system device, Japanese Patent application Laid-Open No. 2002-185956, for example, has proposed one of the remotely monitoring system devices, in which one an image displayed in a receiving side of the system device at a time when the camera is in motion is shifted and displayed so as to approach its real-time image supposed to appear in a current shooting area of the camera. This makes it possible to provide the monitoring system device, which is remotely controlled through the camera in a manner such that a displayed range of the image in the receiving side of the system device is processed so as to: have the displayed image have every appearance of being a real-time image supposed to appear in the current shooting area; and, provide the displayed image as if it were free from any time delay in displaying it in the receiving side of the system device.
These conventional techniques mentioned above are however based on the premise that motion pictures are transmitted through a wire circuit. Therefore, it is possible for these techniques to transmit the motion pictures free from any feeling of disorder by making a correction to a fixed time delay caused in the wire circuit. On the other hand, in case that the motion pictures are transmitted through a wireless circuit such as the Internet and a wireless LAN, it is impossible to obtain a constant communication speed. This leads to a fluctuation in arrival time of data of the motion pictures.
In other words, a variation in communication delay leads to a variation in image plotting timing. This leads often to a communication error, which leads to an occasional loss of data. As a result, the motion pictures suffering from a feeling of disorder are displayed (See FIGS. 20, 21 and 22) in the receiving side of the device.
As is clear from the above reasons, in case that an operator operates a moving unit such as a model car and the like carrying a camera such as one described in the above by monitoring an image shot by the camera and displayed on a monitor of a personal computer and the like, such a fluctuation described above disturbs the motion pictures so as to impair a smooth and continuous stream of the motion pictures. Namely, such a fluctuation leads to the discontinuity in data stream of the motion pictures. Due to the presence of this discontinuity in the data stream of the motion pictures, it is impossible for the operator to forecast the moving unit's motion and therefore impossible to assume precise control of the moving unit. This impairs the controllability of the moving unit.
As countermeasures against the above problems, a conventional method for suppressing a fluctuation accumulates data of the motion pictures, which data is capable of covering a variation range of the fluctuation and accumulated in the receiving side in communication. However, such countermeasures mentioned above suffers from occurrence of a time delay in motion pictures, wherein such a time delay corresponds to an amount of the data of the motion pictures thus accumulated.